As is well known, consumers demand a choice between many different models of automobiles. Depending on the circumstances, some consumers might desire a simple yet effective automobile, with the principal and indeed overriding consideration being cost. With this in mind, the present invention recognizes that it is possible to provide an effective and useful automobile, the cost of which can be minimized by minimizing the weight of the automobile and by using the novel structure disclosed herein.
More specifically, the present invention recognizes that a useful, low-cost, lightweight automobile can be provided which has a molded plastic body consisting essentially of a molded left half side bonded to a molded right half side. After molding, the body is attached to a steel frame which supports the body and drive components. It will readily be appreciated that a molded plastic body is both lightweight, compared to metal automobile bodies, and relatively inexpensive.
As further recognized by the present invention, however, it is not sufficient to simply bolt a plastic body to a steel frame, in contrast to present steel-bodied automobiles. More specifically, in contrast to present steel automobile bodies, mechanical expansions and contractions of plastic automobile bodies that are attributable to ambient temperature changes (referred to herein as "thermal expansion") occur at a rate that is faster than the thermal expansion rate for steel. Consequently, simply bolting portions of the body to the frame (and thereby constraining movement of the bolted portions) could result in cracking of the bolted portions as the body thermally expands or contracts. Thus, the means for attaching the body to the frame must account for this difference between the steel and plastic thermal expansion rates, while nevertheless effecting a firm attachment of the body to the frame.
Moreover, the present invention recognizes that a plastic automobile body should be relatively stiff. Accordingly, as recognized herein the means for attaching a molded plastic body to a steel frame ideally adds stiffness to the automobile structure. Additionally, the present invention recognizes that the means for attaching a molded plastic body to a steel frame also ideally reduces the likelihood of the plastic body peeling away from the portion of the frame to which it is attached. As still further recognized by the present invention, the means for attaching a plastic body to a steel frame is preferably relatively inexpensive, yet effective.
Accordingly, it is an object of the present invention to provide a means for attaching a plastic automobile body to a steel automobile frame which accounts for variations between the thermal expansion rate of the body and the thermal expansion rate of the frame. Another object of the present invention is to provide a means for firmly attaching a plastic automobile body to a steel automobile frame that incorporates a relatively simple design. Still another object of the present invention is to provide a means for firmly attaching a plastic automobile body to a steel automobile frame that adds stiffness to the automobile structure. Yet another object of the present invention is to provide a means for firmly attaching a plastic automobile body to a steel automobile frame that is easy to use and cost-effective.